Polymerizable fluorinated ester compounds and their preparing processes

ABSTRACT

Polymerizable fluorinated ester compounds having formulae (1) and (2) are novel wherein R 1  is H, methyl or trifluoromethyl, R 2  and R 3  are H or a monovalent hydrocarbon group, R 2  and R 3  may form a ring, R 4  is H, OH or a monovalent hydrocarbon group, and R 5  is an acid labile group. They are useful as monomers to produce polymers for the manufacture of radiation-sensitive resist compositions which have high transparency to radiation having a wavelength of up to 500 nm and exhibit good development properties due to the presence of phenol-like acidic hydroxyl groups

CROSS-REFERENCE TO RELATED APPLICATION

This non-provisional application claims priority under 35 U.S.C. §119(a)on Patent Application No. 2003-348104 filed in Japan on Oct. 7, 2003,the entire contents of which are hereby incorporated by reference.

TECHNICAL FIELD

This invention relates to novel polymerizable fluorinated estercompounds and processes for preparing the same. The polymerizablefluorinated ester compounds are useful as raw materials for thesynthesis of polymers, functional materials, pharmaceutical andagricultural chemicals, and most useful as monomers to produce polymersfor the manufacture of radiation-sensitive resist compositions which arefully transparent to radiation having a wavelength of up to 500 nm,especially up to 200 nm, typically ArF and F₂ laser beams, and have goodresistance to dry etching.

BACKGROUND ART

While a number of recent efforts are being made to achieve a finerpattern rule in the drive for higher integration and operating speeds inLSI devices, deep-ultraviolet lithography is thought to hold particularpromise as the next generation in microfabrication technology. Inparticular, photolithography using a KrF, ArF or F₂ laser as the lightsource is strongly desired to reach the practical level as themicropatterning technique capable of achieving a feature size of 0.3 μmor less. Various alkali-soluble resins are used as the base resin insuch resists.

For KrF laser resists, a polyhydroxystyrene resin having phenolichydroxyl groups as the alkali-soluble functional group is, in fact, astandard base resin. For ArF laser resists, poly(meth)acrylate resinsand resins comprising polymerized units of cycloaliphatic olefin such asnorbornene, using carboxyl groups as the alkali-soluble group, are underinvestigation. Of these, the poly(meth)acrylate resins are regarded, dueto ease of polymerization, as a promising candidate for practical use.These resist resins using carboxyl groups as the alkali-solublefunctional group, having a higher acidity than phenolic hydroxyl groups,however, tend to encounter difficulty of dissolution control, oftenleading to pattern collapse caused by swelling or the like.

Functional groups having an acidity comparable to phenolic hydroxylgroups are desired. It was proposed to use an alcohol having pluralfluorine atom substitution at α- and α′-positions (e.g., having apartial structure: —C(CF₃)₂OH) as the alkali-soluble functional group,as described in G. Wallraff et al., Active Fluororesists for 157 nmlithography in 2nd International Symposium on 157 nm Lithography.Styrene and norbornene derivatives having fluoroalcohol —C(CF₃)₂OHincorporated therein are proposed as monomers used in the manufacture ofbase resins. Similar examples of fluoroalcohol-substituted norborneneare found in JP-A 2003-192729 and JP-A 2002-72484. For thepolymerization of norbornene monomers, however, radical polymerizationof monomers of the same type is difficult, and instead, specialpolymerization techniques such as coordinate polymerization andring-opening metathesis polymerization, using unique transition metalcatalysts are necessary. Although alternating copolymerization of anorbornene monomer with a comonomer such as maleic anhydride ormaleimide can be performed by radical polymerization, the presence ofcomonomer imposes a substantial limit on the freedom of resin design.

JP-A 2003-040840 describes fluoroalcohol-substituted acrylate monomers.Although the method of preparing these monomers is not definite, thestarting material used is hexafluoroacetone (boiling point −27° C.)which is awkward to handle because it is gaseous at room temperature.The synthesis of polymerizable compound must follow long steps, leavingthe problem that commercial preparation is difficult.

There is a strong demand to develop an easily prepared polymerizablecompound having both a (meth)acrylate structure that facilitatespolymerization or making a resist resin and a functional group that hasan acidity comparable to phenolic hydroxyl.

SUMMARY OF THE INVENTION

An object of the invention is to provide novel polymerizable fluorinatedester compounds which are useful as monomers to produce resist baseresins that are fully transparent to radiation having a wavelength of upto 500 nm, especially up to 200 nm, and have good development propertiesand good resistance to dry etching and which can be prepared fromreadily available raw materials. Another object is to provide processesfor preparing the same.

The inventor has found that polymerizable fluorinated ester compoundshaving the general formulae (1) and (2) can be readily prepared in highyields from readily available raw materials by the processes to bedescribed later; that these compounds are polymerizable by industriallyapplicable methods such as radical polymerization; and that the use ofresins resulting from polymerization of the ester compounds offersradiation-sensitive resist materials having improved transparency atwavelength 200 nm or less, improved etching resistance and gooddevelopment properties.

In one aspect, the invention provides a polymerizable fluorinated estercompound having the general formula (1) or (2).

Herein R¹ is hydrogen, methyl or trifluoromethyl, R² and R³ are eachindependently hydrogen or a monovalent hydrocarbon group of 1 to 15carbon atoms which may contain at least one hetero atom, a pair of R²and R³ may bond together to form a ring with the carbon atom to whichthey are bonded, and each of R² and R³ is a divalent hydrocarbon groupof 1 to 15 carbon atoms which may contain at least one hetero atom whenthey form a ring, R⁴ is hydrogen, hydroxyl, or a monovalent hydrocarbongroup of 1 to 15 carbon atoms which may contain at least one heteroatom, and R⁵ is an acid labile group.

In another aspect, the invention provides processes for preparingpolymerizable fluorinated ester compounds.

A first embodiment is a process for preparing a polymerizablefluorinated ester compound having the general formula (1), comprisingthe steps of reacting a ketoalcohol compound having the general formula(3) with a compound of the general formula: R⁴—Z to form a diol compoundhaving the general formula (4), and acylating the diol compound to forma polymerizable fluorinated ester compound having the general formula(1).

Herein R¹ to R⁴ are as defined above, and Z is such a monovalent groupthat R⁴—Z provides a R⁴ anion equivalent.

A second embodiment is a process for preparing a polymerizablefluorinated ester compound having the general formula (1), comprisingthe steps of reacting a ketoalcohol compound having the general formula(3) with a compound of the general formula: R⁴—Z to form a diol compoundhaving the general formula (4), protecting one of the two hydroxylgroups of the diol compound to form an alcohol compound having thegeneral formula (5), acylating the alcohol compound to form a protectedpolymerizable fluorinated ester compound having the general formula (6),and deprotecting the compound of formula (6) into a polymerizablefluorinated ester compound having the general formula (1).

Herein R¹ to R⁴ and Z are as defined above, R⁶ is a protective group.

A third embodiment is a process for preparing a polymerizablefluorinated ester compound having the general formula (2), comprisingthe steps of reacting a ketoalcohol compound having the general formula(3) with a compound of the general formula: R⁴—Z to form a diol compoundhaving the general formula (4), protecting one of the two hydroxylgroups of the diol compound with an acid labile group to form an alcoholcompound having the general formula (7), and acylating the alcoholcompound to form a polymerizable fluorinated ester compound having thegeneral formula (2).

Herein R¹ to R⁵ and Z are as defined above.

A fourth embodiment is a process for preparing a polymerizablefluorinated ester compound having the general formula (2), comprisingthe step of protecting a polymerizable fluorinated ester compound havingthe general formula (1) with an acid labile group to form apolymerizable fluorinated ester compound having the general formula (2).

Herein R¹ to R⁵ are as defined above.

The polymerizable fluorinated ester compounds of the invention arenovel. They are useful as raw materials for the synthesis of polymers,functional materials, pharmaceutical and agricultural chemicals. Theyare most useful as monomers to produce polymers for the manufacture ofradiation-sensitive resist compositions which have high transparency toradiation having a wavelength of up to 500 nm, especially up to 200 nm,and exhibit good development properties due to the presence ofphenol-like acidic hydroxyl groups.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the first embodiment, the polymerizable fluorinated ester compoundsof the invention have the general formula (1) or (2).

Herein R¹ is hydrogen, methyl or trifluoromethyl.

R² and R³ are each independently hydrogen or a monovalent hydrocarbongroup of 1 to 15 carbon atoms which may contain at least one heteroatom. Suitable monovalent hydrocarbon groups of 1 to 15 carbon atomswhich may contain at least one hetero atom include straight, branched orcyclic alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl,sec-butyl, tert-butyl, tert-amyl, pentyl, hexyl, octyl, nonyl, decyl,cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentylmethyl,cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl,and cyclohexylbutyl; aryl groups such as phenyl, methylphenyl, naphthyl,anthryl, and phenanthryl; and aralkyl groups such as benzyl,diphenylmethyl and phenethyl. In the foregoing groups, some hydrogenatoms may be substituted with halogen atoms, alkyl groups, aryl groups,alkoxy groups, alkoxycarbonyl groups, oxo groups or the like. A pair ofR² and R³ may bond together to form a ring with the carbon atom to whichthey are bonded. In that event, R² and R³ each stand for a divalenthydrocarbon group of 1 to 15 carbon atoms which may contain at least onehetero atom. Suitable rings formed by R² and R³ include cyclopropane,cyclobutane, cyclopentane, cyclohexane, bicyclo[2.2.1]heptane,bicyclo[2.2.2]octane, tricyclo[5.2.1.0^(2,6)]decane, and adamantane. Inthese rings, some hydrogen atoms may be substituted with halogen atoms,alkyl groups, aryl groups, alkoxy groups, alkoxycarbonyl groups, oxogroups or the like.

R⁴ is hydrogen, hydroxyl, or a monovalent hydrocarbon group of 1 to 15carbon atoms which may contain at least one hetero atom. Examples of themonovalent hydrocarbon group are the same as exemplified above for R²and R³.

R⁵ is an acid labile group. The acid labile group may be selected from avariety of such groups. Examples of the acid labile group are groups ofthe following general formulae (L1) to (L4), tertiary alkyl groups of 4to 20 carbon atoms, preferably 4 to 15 carbon atoms, trialkylsilylgroups in which each alkyl moiety has 1 to 6 carbon atoms, and oxoalkylgroups of 4 to 20 carbon atoms.

In these formulae and throughout the specification, a broken linedenotes a valence bond. R^(L01) and R^(L02) are hydrogen or straight,branched or cyclic alkyl groups of 1 to 18 carbon atoms, preferably 1 to10 carbon atoms. Exemplary alkyl groups include methyl, ethyl, propyl,isopropyl, n-butyl, sec-butyl, tert-butyl, cyclopentyl, cyclohexyl,2-ethylhexyl, and n-octyl. R^(L03) is a monovalent hydrocarbon group of1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, which may containat least one hetero atom such as oxygen, examples of which includeunsubstituted straight, branched or cyclic alkyl groups and straight,branched or cyclic alkyl groups in which some hydrogen atoms arereplaced by hydroxyl, alkoxy, oxo, amino, alkylamino or the like.Illustrative examples are the substituted alkyl groups shown below.

A pair of R^(L01) and R^(L02), R^(L01) and R^(L03), or R^(L02) andR^(L03) may bond together to form a ring. Each of R^(L01), R^(L02) andR^(L03) is a straight or branched alkylene group of 1 to 18 carbonatoms, preferably 1 to 10 carbon atoms when they form a ring.

R^(L04) is a tertiary alkyl group of 4 to 20 carbon atoms, preferably 4to 15 carbon atoms, a trialkylsilyl group in which each alkyl moiety has1 to 6 carbon atoms, an oxoalkyl group of 4 to 20 carbon atoms, or agroup of formula (L1). Exemplary tertiary alkyl groups are tert-butyl,tert-amyl, 1,1-diethylpropyl, 2-cyclopentylpropan-2-yl,2-cyclohexylpropan-2-yl, 2-(bicyclo[2.2.1]heptan-2-yl)propan-2-yl,2-(adamantan-1-yl)propan-2-yl, 1-ethylcyclopentyl, 1-butylcyclopentyl,1-ethylcyclohexyl, 1-butylcyclohexyl, 1-ethyl-2-cyclopentenyl,1-ethyl-2-cyclohexenyl, 2-methyl-2-adamantyl, and 2-ethyl-2-adamantyl.Exemplary trialkylsilyl groups are trimethylsilyl, triethylsilyl, anddimethyl-tert-butylsilyl. Exemplary oxoalkyl groups are 3-oxocyclohexyl,4-methyl-2-oxooxan-4-yl, and 5-methyl-2-oxooxolan-5-yl. Letter y is aninteger of 0 to 6.

R^(L05) is a monovalent C₁-C₈ hydrocarbon group which may contain atleast one hetero atom or a substituted or unsubstituted C₆-C₂₀ arylgroup. Examples of the monovalent hydrocarbon group which may contain atleast one hetero atom include straight, branched or cyclic alkyl groupssuch as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl,tert-butyl, tert-amyl, n-pentyl, n-hexyl, cyclopentyl, and cyclohexyl,and substituted forms of the foregoing groups in which some hydrogenatoms are replaced by hydroxyl, alkoxy, carboxy, alkoxycarbonyl, oxo,amino, alkylamino, cyano, mercapto, alkylthio, sulfo or other groups.Exemplary aryl groups are phenyl, methylphenyl, naphthyl, anthryl,phenanthryl, and pyrenyl. Letter m is equal to 0 or 1, n is equal to 0,1, 2 or 3, and 2 m+n is equal to 2 or 3.

R^(L06) is a monovalent C₁-C₈ hydrocarbon group which may contain atleast one hetero atom or a substituted or unsubstituted C₆-C₂₀ arylgroup. Examples of these groups are the same as exemplified for R^(L05).

R^(L07) to R^(L16) independently represent hydrogen or monovalent C₁-C₁₅hydrocarbon groups which may contain at least one hetero atom. Exemplaryhydrocarbon groups are straight, branched or cyclic alkyl groups such asmethyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl,tert-amyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, cyclopentyl,cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl,cyclohexylmethyl, cyclohexylethyl and cyclohexylbutyl, and substitutedforms of the foregoing groups in which some hydrogen atoms are replacedby hydroxyl, alkoxy, carboxy, alkoxycarbonyl, oxo, amino, alkylamino,cyano, mercapto, alkylthio, sulfo or other groups. Alternatively,R^(L07) to R^(L16), taken together, form a ring (for example, a pair ofR^(L07) and R^(L08), R^(L07) and R^(L09), R^(L08) and R^(L10), R^(L09)and R^(L10) R^(L11) and R^(L12) R^(L13) and R^(L14), or a similar pairform a ring). Each of R^(L07) to R^(L16) represents a divalent C₁-C₁₅hydrocarbon group which may contain at least one hetero atom, when theyform a ring, examples of which are the ones exemplified above for themonovalent hydrocarbon groups, with one hydrogen atom being eliminated.Two of R^(L07) to R^(L10) which are attached to adjoining carbon atoms(for example, a pair of R^(L07) and R^(L09), R^(L09) and R^(L15) R^(L13)and R^(L15) or a similar pair) may bond together directly to form adouble bond.

Of the acid labile groups of formula (L1), the straight and branchedones are exemplified by the following groups.

Of the acid labile groups of formula (L1), the cyclic ones are, forexample, tetrahydrofuran-2-yl, 2-methyltetrahydrofuran-2-yl,tetrahydropyran-2-yl, and 2-methyltetrahydropyran-2-yl.

Examples of the acid labile groups of formula (L2) includetert-butoxycarbonyl, tert-butoxycarbonylmethyl, tert-amyloxycarbonyl,tert-amyloxycarbonylmethyl, 1,1-diethylpropyloxycarbonyl,1,1-diethylpropyloxycarbonylmethyl, 1-ethylcyclopentyloxycarbonyl,1-ethylcyclopentyloxycarbonylmethyl, 1-ethyl-2-cyclopentenyloxycarbonyl,1-ethyl-2-cyclopentenyloxycarbonylmethyl, 1-ethoxyethoxycarbonylmethyl,2-tetrahydropyranyloxycarbonylmethyl, and2-tetrahydrofuranyloxycarbonylmethyl groups.

Examples of the acid labile groups of formula (L3) include1-methylcyclopentyl, 1-ethylcyclopentyl, 1-n-propylcyclopentyl,1-isopropylcyclopentyl, 1-n-butylcyclopentyl, 1-sec-butylcyclopentyl,1-cyclohexylcyclopentyl, 1-(4-methoxy-n-butyl)cyclopentyl,1-methylcyclohexyl, 1-ethylcyclohexyl, 3-methyl-1-cyclopenten-3-yl,3-ethyl-1-cyclopenten-3-yl, 3-methyl-1-cyclohexen-3-yl, and3-ethyl-1-cyclohexen-3-yl groups.

Examples of the acid labile groups of formula (L4) include the followinggroup. The broken line shows the bonding position and direction.

Examples of the tertiary C₄-C₂₀ alkyl groups, trialkylsilyl groups inwhich each alkyl moiety has 1 to 6 carbon atoms, and C₄-C₂₀ oxoalkylgroups are as exemplified for R^(L04).

In formulae (1) and (2), R², R³, R⁴ and R⁵ may be suitably selected inview of various properties (such as transparency, etching resistance anddissolution) of a resist resin resulting from polymerization of thepolymerizable fluorinated ester compound.

Depending on the type of R², R³, R⁴ and OR⁵, the carbon atom to whichthey are bonded can be an asymmetric carbon atom, which means thepresence of enantiomers or diastereomers. The general formula (1) or (2)collectively represents all such stereoisomers. The stereoisomers may beused alone or as a mixture.

Illustrative, non-limiting examples of the polymerizable fluorinatedester compounds of the invention are given below. In the followingformulae, Me is methyl, t-Bu is tert-butyl, and Ph is phenyl.

Next, processes of preparing the polymerizable fluorinated estercompounds of the invention are described.

The starting material is a ketoalcohol compound (3). It can be readilysynthesized by reacting a carbonyl compound (8) with an enolate(1,1,3,3,3-pentafluoro-2-propenyl oxide) which is prepared from1,1,1,3,3,3-hexafluoro-2-propanol (which is commercially available inbulk, liquid at room temperature due to a melting point of −4° C. to −2°C. and a boiling point of 59-60° C., and easy to handle). See T. Nakaiet al., Tetrahedron Letters, Vol. 29, p. 4119, 1988 and T. Nakai et al.,Organic Syntheses, Vol. 76, p. 151, 1998. In this nucleophilic additionreaction of fluoroenolate to carbonyl compound, various aldehydes andketones may be used as the carbonyl compound (8).

The ketoalcohol compound (3) thus produced is sometimes available in theform of a hydrate of the general formula (9) in which water is added tothe carbonyl group, when subjected to work-up process using water, or anoxetane hemi-acetal compound of the general formula (10) in which thehydroxyl group is added intramolecularly to the carbonyl group, or amixture of these three.

Herein, such reaction products are collectively represented by thegeneral formula (3) because in some cases, the mixture can be directlyused in the subsequent reaction, and in some other cases, equilibriumcan be biased toward the ketoalcohol compound by simple dehydratingoperation, prior to the subsequent reaction.

In the event R² and R³ are different, the carbon atom to which they arebonded becomes asymmetric carbon. In the oxetane hemi-acetal compound(10), the carbon atom to which CF₃ and hydroxyl groups are bondedbecomes asymmetric carbon. This means the presence of enantiomers ordiastereomers. The general formula (3) collectively represents all suchstereoisomers. The stereoisomers may be used alone or as a mixture.

If this ketoalcohol compound (3) equivalent (equilibrium mixture) isdirectly acylated, there can be formed a product in which the hydroxylgroup on the oxetane compound (10) is acylated, but not a keto estercompound in which the hydroxyl group on the compound (3) is acylated.For this reason, it is preferred that reaction with R⁴—Z precedeacylation.

A first process of preparing the polymerizable fluorinated estercompounds of the invention involves reacting a ketoalcohol compoundhaving the general formula (3) with a compound of the general formula:R⁴—Z to form a diol compound having the general formula (4), andacylating the diol compound to form a polymerizable fluorinated estercompound having the general formula (1).

In the formulae, as previously defined, R¹ is hydrogen, methyl ortrifluoromethyl, R² and R³ are each independently hydrogen or amonovalent hydrocarbon group of 1 to 15 carbon atoms which may containat least one hetero atom, a pair of R² and R³ may bond together to forma ring, and if so, each of R² and R³ is a divalent hydrocarbon group of1 to 15 carbon atoms which may contain at least one hetero atom, R⁴ ishydrogen, hydroxyl, or a monovalent hydrocarbon group of 1 to 15 carbonatoms which may contain at least one hetero atom, and Z is such amonovalent group that R⁴—Z provides a R⁴ anion equivalent.

In the first step, the starting reactant, ketoalcohol compound (3) isreacted with a compound R⁴—Z.

This reaction is performed by combining the compound (3) with R⁴—Z in asolvent or without solvent. R⁴—Z represents a R⁴ anion equivalent and issuitably selected depending on the desired type of R⁴. Examples of R⁴—Zinclude water (wherein R⁴ is hydroxyl), alkyl metals (wherein R⁴ is ahydrocarbon group) such as methyllithium, butyllithium, phenyllithium,methylmagnesium chloride, ethylmagnesium chloride, and phenylmagnesiumchloride, metal hydrides (wherein R⁴ is a hydrogen atom) such as sodiumhydride, potassium hydride, calcium hydride, aluminum hydride, borane,and diisobutylaluminum hydride, and metal hydrogen complexes or alkyland alkoxy derivatives thereof (wherein R⁴ is a hydrogen atom) such assodium borohydride and lithium aluminum hydride. An appropriate amountof R⁴—Z used is from 1 mole to a large excess per mole of the compound(3). A more appropriate amount of R⁴—Z is from 2 moles to a large excessper mole of the compound (3) because free hydroxyl group is present inthe ketoalcohol compound (3) as the reaction substrate.

When the reaction is performed in a solvent, the solvent used isselected from among hydrocarbons such as hexane, heptane, benzene,toluene, xylene and cumene, ethers such as dibutyl ether, diethyleneglycol diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuranand 1,4-dioxane, nitriles such as acetonitrile, ketones such as acetone,esters such as ethyl acetate, and aprotic polar solvents such asN,N-dimethylformamide and hexamethylphosphoric triamide, alone or asmixtures of any.

For the addition reaction, an appropriate reaction temperature may beselected depending on the type of R⁴—Z. The reaction temperature istypically from −50° C. to approximately the boiling point of thesolvent, preferably from −20° C. to 100° C. It is desired for higheryields that the reaction time is determined by monitoring the progressof reaction by gas chromatography (GC) or thin-layer chromatography(TLC). The reaction time is usually about 0.1 hour to about 50 hours.After the completion of reaction, the target diol compound (4) isseparated from the reaction mixture by a conventional aqueous work-upprocedure. If necessary, the compound (4) can be purified by anyconventional technique such as recrystallization, chromatography ordistillation.

The second step is to acylate the diol compound (4). In this step, theregio-selectivity of reaction is a issue since the diol compound (4) hastwo hydroxyl groups which can be potentially acylated. That is, therecan be produced the target compound (1) and a regioisomer having thegeneral formula (1′).

The compound (1) is selectively obtained in some cases, for example,when the two hydroxyl groups on the diol compound (4) are distinguishedby steric hindrance so that the desired position to be acylated issterically less hindered, or when reaction conditions are properlycontrolled because the two hydroxyl groups have different aciditydespite an approximately equal extent of steric hindrance. In thesecases, the diol compound (4) can be used as the reaction substratewithout any manipulation, i.e., without protecting any hydroxyl group,and subjected to acylation reaction to be described later. This processis of great commercial worth due to shorter or fewer steps involved, ascompared with the process requiring protecting and deprotecting steps tobe described later.

For the acylation reaction, conventional esterification methods, such asreaction with acylating agents, reaction with carboxylic acids andtransesterification are applicable.

In the reaction using acylating agents, the diol compound (4), anacylating agent and a base are sequentially or simultaneously mixed,preferably in a solvent where reaction takes place. Examples of thesolvent used herein include chlorinated solvents such as methylenechloride, chloroform and trichloroethylene, hydrocarbons such as hexane,heptane, benzene, toluene, xylene and cumene, ethers such as dibutylether, diethylene glycol diethyl ether diethylene glycol dimethyl ether,tetrahydrofuran, and 1,4-dioxane, nitriles such as acetonitrile, ketonessuch as acetone and 2-butanone, esters such as ethyl acetate and n-butylacetate, and aprotic polar solvents such as N,N-dimethylformamide,dimethyl sulfoxide, and hexamethylphosphoric triamide, alone or asmixtures of any. Examples of the acylating agent include acid halidessuch as acryloyl chloride, methacryloyl chloride, acryloyl bromide,methacryloyl bromide, and α-trifluoromethylacryloyl chloride, and acidanhydrides such as acrylic anhydride, methacrylic anhydride,α-trifluoromethylacrylic anhydride, acrylic acid/trifluoroacetic acidmixed anhydride, methacrylic acid/trifluoroacetic acid mixed anhydride,α-trifluoromethylacrylic acid/trifluoroacetic acid mixed anhydride,acrylic acid/p-nitrobenzoic acid mixed anhydride, methacrylicacid/p-nitrobenzoic acid mixed anhydride, acrylic acid/ethylcarbonicacid mixed anhydride, and methacrylic acid/ethylcarbonic acid mixedanhydride. Examples of the base include triethylamine,diisopropylethylamine, N,N-dimethylaniline, pyridine, and4-dimethylaminopyridine. An appropriate reaction temperature may beselected depending on the type of acylating agent used and otherreaction conditions. The reaction temperature is typically from −50° C.to approximately the boiling point of the solvent, preferably from −20°C. to room temperature. An appropriate amount of the acylating agentused is from 1 to 40 moles, more preferably 1 to 5 moles per mole of thediol compound (4), though it depends on the structure of the agent.

In the course of reaction using the acylating agent, a regioisomer (1′)may form as a main product at the initial phase of reaction, and as thereaction continues longer, gradual isomerization into the targetcompound (1) may take place. It accounts for this phenomenon that underbasic conditions, the hydroxyl group having a higher acidity(susceptible to deprotonation by base) is acylated at the initial phaseso that the regioisomer (1′) is likely to form as a kinetic product, butthe target compound (1) which is believed to be more stable in thesystem as a thermodynamic product accumulates over a long term ofreaction.

The reaction with carboxylic acids is a dehydrating reaction from acorresponding carboxylic acid, i.e., any of acrylic acid, methacrylicacid and α-trifluoromethylacrylic acid and the reactant, diol compound(4), which is generally performed in the presence of an acid catalyst.An appropriate amount of carboxylic acid used is 1 to 40 moles, morepreferably 1 to 5 moles per mole of the diol compound (4), though itdepends on the structure of acid. Examples of the acid catalyst includeinorganic acids such as hydrochloric acid, hydrobromic acid, sulfuricacid, and nitric acid, and organic acids such as oxalic acid,trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid, andp-toluenesulfonic acid, alone or as mixtures of any. An appropriateamount of the acid catalyst used is 0.001 to 1 mole, more preferably0.01 to 0.05 mole per mole of the diol compound (4). Examples of thesolvent used are as exemplified above for the reaction with theacylating agent. The reaction temperature is preferably from −50° C. toapproximately the boiling point of the solvent. The reaction may also beperformed in a solvent comprising a hydrocarbon such as hexane, heptane,benzene, toluene, xylene or cumene, removing water formed out of thesystem by azeotropy. In this embodiment, the water may be distilled offheating the solvent under reflux at the boiling point in atmosphericpressure, or the water be distilled off under reduced pressure at alower temperature than the boiling point.

The transesterification is implemented by reacting the reactant, diolcompound (4) with a corresponding carboxylic acid ester, i.e., any ofacrylate, methacrylate and α-trifluoromethylacrylate in the presence ofa catalyst and removing the alcohol formed. The carboxylic acid estersused are preferably primary alkyl esters. Inter alia, methyl, ethyl andn-propyl esters are preferred because of low cost and ease of reactionprogress. An appropriate amount of carboxylic acid ester used is 1 to 40moles, more preferably 1 to 5 moles per mole of the diol compound (4),though it depends on the structure of ester. Examples of the catalystinclude inorganic acids such as hydrochloric acid, hydrobromic acid,sulfuric acid, and nitric acid, organic acids such as oxalic acid,trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid, andp-toluenesulfonic acid, bases such as sodium methoxide, sodium ethoxide,potassium t-butoxide, and 4-dimethylaminopyridine, and salts such assodium cyamide, potassium cyamide, sodium acetate, potassium acetate,calcium acetate, tin acetate, aluminum acetate, aluminum acetoacetate,alumina, and Lewis acids such as aluminum trichloride, aluminumethoxide, aluminum isopropoxide, boron trifluoride, boron trichloride,boron tribromide, tin tetrachloride, tin tetrabromide, dibutyltindichloride, dibutyltin dimethoxide, dibutyltin oxide, titaniumtetrachloride, titanium tetrabromide, titanium(IV) methoxide,titanium(IV) ethoxide, titanium(IV) isopropoxide, and titanium(IV)oxide, alone or as mixtures of any. An appropriate amount of thecatalyst used is 0.001 to 20 moles, more preferably 0.01 to 0.05 moleper mole of the diol compound (4). The reaction may be performed in asolventless system (the reagent, carboxylic acid ester itself may serveas a solvent), which is preferred in that extra operations such asconcentration and solvent recovery are eliminated. A solvent may be usedin a supplemental manner for the purpose of preventing polymerization ofthe target compound and reagent. Examples of the solvent, if used,include hydrocarbons such as hexane, heptane, benzene, toluene, xyleneand cumene, and ethers such as dibutyl ether, diethylene glycol diethylether, diethylene glycol dimethyl ether, tetrahydrofuran, and1,4-dioxane, alone or in admixture. An appropriate reaction temperaturemay be selected depending on the type of carboxylic acid ester used andother reaction conditions. Usually, the reaction is performed atelevated temperature. Better results are obtained when the reaction isperformed at a temperature approximate to the boiling point of a lowboiling point alcohol formed by transesterification reaction such asmethanol, ethanol or 1-propanol, whereby the alcohol formed is distilledoff during the reaction. The alcohol may be distilled off at a lowertemperature than the boiling point under reduced pressure.

It is desired for higher yields that the time of acylating reaction isdetermined by monitoring the progress of reaction (including not onlyacylating reaction, but also isomerization) by GC or TLC. The reactiontime is usually about 0.1 hour to about 240 hours. After the completionof reaction, the target fluorinated ester compound (1) is isolated fromthe reaction mixture by a conventional work-up such as aqueous work-upor concentration.

If necessary, the compound (1) can be purified by any conventionaltechnique such as recrystallization, chromatography or distillation. Thetarget compound (1) and its regioisomer (1′) may be separated by such apurifying technique. Alternatively, a mixture of compounds (1) and (1′)may be used in the subsequent step like the manufacture of resin. Themolar ratio of isomers (1) and (1′) may have any arbitrary value from 0to 1 although the molar ratio of compound (1) having a phenol-likeacidity should preferably be at least 0.3, more preferably at least 0.5.

The reaction intermediate (4) and the target compound (1) have apossibility that depending on the type of R², R³ and R⁴, the carbonatoms to which they are bonded become asymmetric carbons, which meansthe presence of enantiomers or diastereomers. The general formula (4) or(1) collectively represents all such stereoisomers. The stereoisomersmay be used alone or as a mixture.

A second process for preparing the polymerizable fluorinated estercompounds of the invention comprises the steps of reacting a ketoalcoholcompound having the general formula (3) with a compound of the generalformula: R⁴—Z to form a diol compound having the general formula (4),protecting one of the hydroxyl groups of the diol compound so as to forman alcohol compound having the general formula (5), acylating thealcohol compound to form a protected polymerizable fluorinated estercompound having the general formula (6), and deprotecting the compoundof formula (6) into a polymerizable fluorinated ester compound havingthe general formula (1). The second process is advantageously employedwhen the first process, that is, direct acylating reaction of diolcompound (4) is less regio-selective.

Herein, R¹ to R⁴, Z and R⁴—Z are as defined above, R⁶ is a protectivegroup.

For the step of reacting a ketoalcohol compound (3) with a compound:R⁴—Z to form a diol compound (4), the same as described for the firstprocess is applicable. For the step of acylating the protected alcoholcompound (5) to form a protected polymerizable fluorinated estercompound (6), the same as described for the first process, directacylating reaction of diol compound (4) to form polymerizablefluorinated ester compound (1) is applicable. In this step of the secondprocess, since the protected alcohol compound (5) has only one hydroxylgroup subject to acylation, reagents including acylating agent,carboxylic acid, and ester may be used in increased equivalent amountsto accelerate the reaction.

The protective group R⁶ includes those groups exemplified above for theacid labile group R⁵ and other protective groups.

When the protective group R⁶ is the acid labile group R⁵, the protectedpolymerizable fluorinated ester compound (6) is identical with thepolymerizable fluorinated ester compound protected with acid labilegroup represented by formula (2). Then the process is a process ofpreparing polymerizable fluorinated ester compounds (2).

Examples of the other protective group include acyl groups such asformyl, benzoylformyl, acetyl, chloroacetyl, dichloroacetyl,trichloroacetyl, trifluoroacetyl, methoxyacetyl, triphenylmethoxyacetyl,phenoxyacetyl, phenylacetyl, nicotinyl, 3-phenylpropionyl, 4-pentenoyl,4-oxopentanoyl, pyvaloyl, 1-adamantoyl, crotonyl, 4-methoxycrotonyl,benzoyl, 4-phenylbenzoyl, and mesytoyl.

The protecting and deprotecting reactions of hydroxyl group widely varywith the type of R⁶ and may be performed in a conventional manner. In anexample where the hydroxyl group is protected with an acyl group,conventional esterification methods may be used. The above-describedreaction with acylating agent, reaction with carboxylic acid andtransesterification are applicable using corresponding reagents. Fordeprotection of acyl group, hydrolysis/solvolysis reaction using acidsor bases, and deprotecting reaction under acidic conditions may beemployed although the de protecting reaction is not limited thereto.

If necessary, the reaction intermediates (4), (5), (6) and targetcompounds (1) and (2) (corresponding to compound (6) wherein theprotective group R⁶ is an acid labile group R⁵) can be purified by anyconventional technique such as recrystallization, chromatography ordistillation. The reaction intermediates (4), (5), (6) and the targetcompounds (1) and (2) have a possibility that depending on the type ofR², R³, R⁴ and OR⁵, the carbon atom to which they are bonded becomesasymmetric carbon, which means the presence of enantiomers ordiastereomers. The general formula (1) or (2) collectively representsall such stereoisomers. The stereoisomers may be used alone or as amixture.

A third process for preparing the polymerizable fluorinated estercompounds of the invention comprises the step of protecting apolymerizable fluorinated ester compound having the general formula (1)with an acid labile group to form a polymerizable fluorinated estercompound having the general formula (2).

Herein, R¹ to R⁵ are as defined above.

The third process is through protection of the target compound (1) withan acid labile group to form the target compound protected with an acidlabile group (2). The type of acid labile group used herein is the sameas described above. The protection reaction may be performed byconventional methods. In an example where the hydroxyl group isprotected with an acyl group, conventional esterification methods may beused. The above-described reaction with acylating agent, reaction withcarboxylic acid and transesterification are applicable usingcorresponding reagents. In another example where an ether group is usedfor protection, reaction with halides under basic conditions, andaddition reaction to unsaturated compounds under acidic conditions areapplicable. In a further example of silyl protection, reaction withchlorosilane under basic conditions is applicable. The protectionreaction is not limited to the foregoing.

If necessary, the target compound (2) can be purified by anyconventional technique such as recrystallization, chromatography ordistillation. The target compound (2) has a possibility that dependingon the type of R², R³, R⁴ and OR⁵, the carbon atoms to which they arebonded become asymmetric carbons, which means the presence ofenantiomers or diastereomers. The general formula (2) collectivelyrepresents all such stereoisomers. The stereoisomers may be used aloneor as a mixture.

Using the polymerizable fluorinated ester compounds of the invention,homopolymers may be prepared by common techniques like radicalpolymerization. Alternatively, copolymers may be prepared bycopolymerization with at least one type of other polymerizable monomer.

Polymers obtained through the polymerization of polymerizablefluorinated ester compounds according to the invention are fullytransparent to radiation having a wavelength of up to 500 nm, especiallyup to 200 nm, and have good development properties due to the presenceof phenol-like acidic hydroxyl groups, when used as the base resin inradiation-sensitive resist compositions. Examples of the radiationhaving a wavelength of up to 200 nm include ArF laser light (193 nm), F₂laser light (157 nm), Ar₂ laser light (126 nm), and extreme ultravioletradiation (EUV 13 nm).

EXAMPLE

Examples of the invention are given below by way of illustration and notby way of limitation.

Example 1 Synthesis of2-(2-hydroxy-2-methyl-1,1,3,3,3-pentafluoro-propyl)-2-adamantylmethacrylate

<1-1> Synthesis of 2-(2-oxo-1,1,3,3,3-pentafluoropropyl)-adamantan-2-olequivalent

With stirring under nitrogen atmosphere, a mixture of 41.5 g of1,1,1,3,3,3-hexafluoro-2-propanol and 500 ml of tetrahydrofuran wascooled to −50° C. To the mixture, 200 ml of 2.46M n-butyllithium inn-hexane was added dropwise. The mixture was stirred at −70° C. for 10minutes and then at 5° C. for 90 minutes. To the reaction mixture, 18.5g of 2-adamantane in 100 ml of tetrahydrofuran was added. The mixturewas stirred at 5° C. for 1 hour and then at room temperature for 18hours. The reaction mixture was mixed 400 ml of 10% hydrochloric acidand extracted with ethyl acetate. Through conventional work-up procedureincluding washing, drying and concentration, there was obtained as acrude product, 36.9 g (quantitative yield) of a mixture of an oxetanehemi-acetal compound, and a hydrate which is an equivalent of the targetketoalcohol compound, in a ratio of about 89:11.

A mixture ofspiro[adamantane-2,2′-(3′,3′-difluoro-4′-hydroxy-4′-trifluoromethyloxetane)]and 2-(2,2-dihydroxy-1,1,3,3,3-pentafluoropropyl)adamantan-2-ol in amolar ratio of about 89:11.

colorless solid

IR (KBr): ν=3588, 3442, 2921, 2865, 1456, 1338, 1203, 1041, 912 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.46-2.41 (14H, m), 6.97 (0.11H, s,adamantyl-OH), 8.11 (2×0.11H, s, two hydroxyl groups of hydrate), 9.44(0.89H, s, oxetane-OH) ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−125.6(0.89F, dq, J=208, 13 Hz), −122.5 (0.89F, d, J=208 Hz), −114.2 (2×0.11F,q, J=13 Hz), −81.7 (3×0.89F, d, J=13 Hz), −81.1 (3×0.11F, t, J=13 Hz)ppm

<1-2> Synthesis of2-(2-hydroxy-2-methyl-1,1,3,3,3-pentafluoropropyl)-adamantan-2-ol

In 800 ml of benzene was dissolved 30 g of the crude product ofketoalcohol compound equivalent obtained in <1-1>. The solution wasstirred and heated under reflux while the water formed was continuouslyremoved. With stirring, the solution was added dropwise to 250 ml of atetrahydrofuran solution of 1.0M methylmagnesium chloride. The mixturewas stirred for 30 minutes at room temperature and then heated underreflux for one hours. After cooling, the reaction mixture was mixed with700 ml of 10% hydrochloric acid and extracted with ethyl acetate.Through conventional work-up procedure including washing, drying andconcentration, a crude product was obtained. Recrystallization fromn-hexane gave 28.9 g (yield 92%) of the target diol compound.

2-(2-hydroxy-2-methyl-1,1,3,3,3-pentafluoropropyl)-adamantan-2-ol

colorless solid

IR (KBr): ν=3355, 3129, 2937, 2921, 2871, 1457, 1292, 1213, 1174, 1074,1039 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.39-1.46 (2H, t-like m), 1.55 (3H, br.s), 1.58-1.73 (5H, m), 1.79 (1H, br. s), 2.12-2.20 (3H, m), 2.22-2.30(2H, t-like m), 2.33 (1H, br. s), 5.34 (1H, s, OH), 6.77 (1H, s, OH) ppm

¹³C-NMR (150 MHz in CDCl₃): δ=19.73, 26.60, 27.11, 32.94, 33.21, 33.57,34.01, 34.09, 34.25, 39.03, 77.51 (t-like, J=24 Hz), 77.10-78.2 (m),123.22 (dd-like, J=260, 267 Hz), 125.60 (q, J=289 Hz) ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−110.5(1F, d-like, J=262 Hz), −107.8 (1F, dq, J=262, 15 Hz), −77.0 (3F, t,J=15 Hz) ppm

<1-3> Synthesis of2-(2-hydroxy-2-methyl-1,1,3,3,3-pentafluoropropyl)-2-adamantylmethacrylate

With stirring at 5° C., 14 ml of triethylamine was added dropwise to amixture of 20 g of the diol compound obtained in <1-2>, 7.4 ml ofmethacryloyl chloride, and 500 ml of methylene chloride. The reactionmixture was stirred at 0° C. for 30 minutes and then at room temperaturefor 48 hours. The reaction was monitored by gas chromatography, findinga higher proportion of a regioisomer at the initial (targetcompound:regioisomer=24:76 after 4 hours), subsequent gradualisomerization into the target compound, and substantial conversion tothe target compound after 48 hours. The reaction mixture was mixed with100 ml of water, stirred at room temperature for 2 hours, and extractedwith diethyl ether. Through conventional work-up procedure includingwashing, drying and concentration, a crude product was obtained.Recrystallization from n-hexane gave 20.7 g (yield 85%) of the targetfluorinated ester compound.

2-(2-hydroxy-2-methyl-1,1,3,3,3-pentafluoropropyl)-2-adamantylmethacrylate

colorless solid

GC-MS (EI): (m/z)⁺=41, 69, 141, 183, 207, 296, 382 (M⁺)

GC-MS (CI, isobutane): (m/z)⁺=277, 297, 383 [(M+H)⁺]

IR (KBr): ν=3494, 2981, 2954, 2927, 2892, 2869, 1710, 1463, 1326, 1286,1214, 1187, 1170, 1095, 1079, 1045 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.50-1.88 (11H, m), 1.91 (3H, s),2.02-2.32 (4H, m), 2.69 (1H, br. s), 3.41 (1H, br. s), 5.71 (1H, br. s),6.04 (1H, br. s), 7.08 (1H, s) ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−107.6(1F, dd, J=277, 1790 Hz), −101.0 (1F, dd-like, J=277, 513 Hz), −76.5(3F, d, J=275 Hz) ppm

Comparative Example 1 Synthesis ofspiro[adamantane-2,2′-(3′,3′-difluoro-4′-trifluoromethyloxetan)]-4′-ylmethacrylate by direct esterification of ketoalcohol compound equivalent

Esterification (methacryloylation) reaction was carried out as in <1-3>in Example 1, aside from using 5.0 g of a crude product of theketoalcohol compound equivalent obtained in <1-1> instead of the diolcompound obtained in <1-2>. The resulting product consisted of 5.5 g(yield 95%) of an ester of the above-identified oxetane compound, withno ester of hydrate being produced. It is thus believed that thereaction proceeded while the equilibrium was biased toward the oxetanecompound.

spiro[adamantane-2,2′-(3′,3′-difluoro-4′-trifluoromethyl-oxetan)]-4′-ylmethacrylate

colorless liquid

IR (KBr): ν=2937, 2863, 1758, 1456, 1334, 1305, 1214, 1126, 1097, 1037,968 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.60-1.98 (15H, m), 2.30-2.33 (2H, m),5.97 (1H, t, J=1 Hz), 6.19 (br. s) ppm

¹³C-NMR (150 MHz in DMSO-d6): δ=18.11, 25.54, 26.08, 31.66, 31.76,31.87, 33.39 (d-like, J=4 Hz), 34.78, 35.00, 35.89, 99.86 (t, J=22 Hz),101.5-103.5 (m), 116.65 (dd, J=282, 296 Hz), 120.13 (q, J=287 Hz),130.21, 134.64, 162.22 ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−123.36(1F, dq, J=208, 13 Hz), −116.70 (1F, d, J=208 Hz), −76.36 (3F, d, J=13Hz) ppm

Example 2 Synthesis of1-(2-hydroxy-1,1,3,3,3-pentafluoropropyl)-1-cyclohexyl methacrylate

<2-1> Synthesis of 1-(2-oxo-1,1,3,3,3-pentafluoropropyl)-cyclohexan-1-olequivalent

Reaction was performed as in <1-1> of Example 1 aside from using 294 gof cyclohexanone instead of the 2-adamantanone in <1-1>. A crude productwas obtained. Recrystallization from n-hexane gave 565 g (yield 71%) ofa hydrate which was an equivalent of the target ketoalcohol compound.

1-(2,2-dihydroxy-1,1,3,3,3-pentafluoropropyl)cyclohexan-1-ol

colorless solid

IR (KBr): ν=3505, 3353, 2954, 2865, 1452, 1307, 1205, 1103, 1076, 1062,979 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.12-1.20 (1H, m), 1.50-1.64 (7H, m),1.97-2.05 (2H, m), 6.39 (1H, br. s, OH), 7.93 (2H, br. s, 2OH) ppm

¹³C-NMR (150 MHz in DMSO-d6): δ=21.67, 26.26, 31.29, 77.32 (t, J=25 Hz),95.40 (hex, J=30 Hz), 118.84 (t, J=262 Hz), 123.63 (q, 292 Hz) ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−123.8(2F, q, J=13 Hz), −81.1 (3F, t, J=13 Hz) ppm

<2-2> Synthesis of1-(2-hydroxy-2-methyl-1,1,3,3,3-pentafluoropropyl)cyclohexan-1-ol

Reaction was performed as in <1-2> of Example 1 aside from using 272 gof the ketoalcohol compound equivalent obtained in <2-1> instead of theketoalcohol compound equivalent obtained in <1-1>. A crude product wasobtained. Recrystallization from n-hexane gave 217 g (yield 80%) of thetarget diol compound.

1-(2-hydroxy-2-methyl-1,1,3,3,3-pentafluoropropyl)-cyclohexan-1-ol

colorless solid

IR (KBr): ν=3448, 3195, 2968, 2954, 2945, 2873, 2861, 1303, 1176, 1087,1054, 985 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.08-1.18 (1H, m), 1.45-1.63 (10H, m),1.81 (1H, d-like, J=12 Hz), 2.02 (1H, d-like, J=13 Hz), 5.16 (1H, br. s,OH), 6.69 (1H, s, OH) ppm

¹³C-NMR (150 MHz in DMSO-d6): δ=20.15, 21.83, 21.95, 26.51, 31.33,32.25, 76.42 (t, J=25 Hz), 77.67 (hex-like, J=26 Hz), 122.31 (dd, J=258,263 Hz), 126.52 (q, J=290 Hz) ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−120.5(1F, dq, J=262, 13 Hz), −118.3 (1F, dq, J=262, 15 Hz), −77.3 (3F,t-like, J=14 Hz) ppm

<2-3> Synthesis of1-(2-hydroxy-2-methyl-1,1,3,3,3-pentafluoropropyl)-1-cyclohexylmethacrylate

Reaction was performed as in <1-3> of Example 1 aside from using 144 gof the diol compound obtained in <2-2> instead of the diol compoundobtained in <1-2>. A crude product was obtained. In this example, thestirring time at room temperature was 18 hours, and the target compoundwas obtained with little of the regioisomer. Recrystallization fromn-hexane gave 154 g (yield 85%) of the target fluorinated estercompound.

1-(2-hydroxy-2-methyl-1,1,3,3,3-pentafluoropropyl)-1-cyclohexylmethacrylate

colorless solid

GC-MS (EI): (m/z)⁺=41, 69, 87, 111, 131, 224, 330 (M⁺)

IR (KBr): ν=3390, 3025, 3000, 2942, 2873, 1706, 1463, 1328, 1164, 1128,1062 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.23-1.30 (2H, m), 1.32-1.41 (1H, m),1.51 (3H, s), 1.57-1.70 (5H, m), 1.92 (3H, s), 2.70-2.75 (1H, m),2.78-2.83 (1H, m), 5.74 (1H, quint-like, J=1 Hz), 6.08 (1H, q-like,J=0.7 Hz), 7.09 (1H, s) ppm

¹³C-NMR (150 MHz in DMSO-d6): δ=19.46, 19.67, 22.30, 22.38, 25.67,29.79, 31.41, 77.80 (hex, J=27 Hz), 86.79 (t, J=27 Hz), 121.23 (t, J=262Hz), 126.15 (q, J=289 Hz), 127.36, 138.16, 165.71 ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−112.8 to−112.9 (2F, m), −77.1 (t, J=14 Hz) ppm

Example 3 Synthesis of1-(1,1,3,3,3-pentafluoro-2-trimethylsilyloxy-propyl)-1-cyclohexylmethacrylate

With stirring at room temperature under nitrogen atmosphere, 38.3 ml oftrimethylsilyl chloride was added dropwise to a solution of 50.0 g ofthe fluorinated ester compound obtained in <2-3> of Example 2 and 41.2 gof imidazole in 300 g of N,N-dimethylformamide. Stirring continued atroom temperature for 16 hours. The reaction mixture was mixed with 500ml of water and extracted with diethyl ether. Through conventionalwork-up procedure including washing, drying and concentration, there wasobtained 59.0 g (yield 97%) of the target fluorinated ester compoundhaving a hydroxyl group protected.

1-(1,1,3,3,3-pentafluoro-2-trimethylsilyloxypropyl)-1-cyclohexylmethacrylate

colorless liquid

IR (NaCl): ν=2944, 2865, 1735, 1454, 1257, 1195, 1184, 1159, 1147, 1132,1058, 981 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=0.17 (9H, s), 1.18-1.36 (3H, m),1.50-1.64 (8H, m), 3.23 (3H, s), 2.61 (1H, d-like, J=12 Hz), 2.79 (1H,d-like, J=13 Hz), 5.69 (1H, t, J=1.4 Hz), 6.03 (1H, s) ppm

¹³C-NMR (150 MHz in DMSO-d6): δ=1.58, 18.10 (2C), 20.82, 20.91, 24.08,28.72, 29.44, 79.50 (hex, J=29 Hz), 84.91 (t, J=27 Hz), 119.09 (t, J=263Hz), 123.95 (q, J=286 Hz), 125.93, 136.59, 164.13 ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−111.93(1F, dq, J=273, 11 Hz), −111.35 (1F, dq, J=273, 11 Hz), −76.30 (3F, t,J=11 Hz) ppm

Example 4 Synthesis of1-(2-methoxymethoxy-1,1,3,3,3-pentafluoro-propyl)-1-cyclohexylmethacrylate

With stirring at room temperature under nitrogen atmosphere, 4.6 ml ofchloromethyl methyl ether was added dropwise to a solution of 5.0 g ofthe fluorinated ester compound obtained in <2-3> of Example 2, 0.1 g ofsodium iodide, and 12.6 ml of diisopropylethylamine in 30 g ofacetonitrile. The mixture was slowly heated to 70° C., at which stirringcontinued for 16 hours. The reaction mixture was cooled, mixed with 500ml of water and extracted with diethyl ether. Through conventionalwork-up procedure including washing, drying and concentration andpurification by silica gel column chromatography, there was obtained 4.6g (yield 81%) of the target fluorinated ester compound having a hydroxylgroup protected.

1-(2-methoxymethoxy-1,1,3,3,3-pentafluoropropyl)-1-cyclohexylmethacrylate

colorless liquid

GC-MS (EI): (m/z)⁺=45, 69, 101, 131, 167, 256, 284, 313, 344

GC-MS (CI, isobutane): (m/z)⁺=101, 131, 267, 375 [(M+1)⁺]

IR (NaCl): ν=2996, 2940, 2865, 1733, 1454, 1321, 1299, 1911, 1160, 1143,1070 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.23-1.37 (3H, m), 1.56-1.70 (8H, m),1.92 (3H, t, J=1.2 Hz), 2.75 (2H, br. d, J=13 Hz), 3.35 (3H, s), 4.80(1H, d, J=7 Hz), 4.97 (1H, d, J=7 Hz), 5.75 (1H, t, J=1.7 Hz), 6.09 (1H,q, J=1.0 Hz) ppm

¹³C-NMR (150 MHz in DMSO-d6): δ=14.34, 19.59, 22.25, 22.40, 25.59,30.46, 57.25, 82.68 (q-like, J=27 Hz), 86.45 (t, J=27 Hz), 93.84, 116.58(d, J=167 Hz), 120.87 (t, J=263 Hz), 125.40 (q, J=288 Hz), 127.51,138.05, 165.72 ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−110.40(2F, q, J=11 Hz), −75.36 (3F, t, J=11 Hz) ppm

Example 5 Synthesis of1-(2-hydroxy-1,1,3,3,3-pentafluoropropyl)-1-cyclohexyl methacrylate

<5-1> Synthesis of1-(2-hydroxy-1,1,3,3,3-pentafluoro-propyl)cyclohexan-1-ol

In 200 ml of benzene was dissolved 24.1 g of the hydrate of ketoalcoholcompound equivalent obtained in <2-1> of Example 2. The solution wasstirred and heated under reflux while the water formed was continuouslyremoved. With stirring at 5° C. under nitrogen atmosphere, the solutionwas added dropwise to a suspension of 9.0 g of lithium aluminum hydridein 200 ml of tetrahydrofuran. The mixture was stirred at roomtemperature for 30 minutes, and then heated under reflux for 4 hours.The reaction mixture was cooled, mixed with 50 ml of acetone, then with250 ml of 20% hydrochloric acid, and extracted with diethyl ether.Through conventional work-up procedure including washing, drying andconcentration, a crude product was obtained. Recrystallization fromn-hexane gave 15.0 g (yield 66%) of the target diol compound.

1-(2-hydroxy-1,1,3,3,3-pentafluoropropyl)cyclohexan-1-ol

colorless solid

GC-MS (EI): (m/z)⁺=43, 55, 81, 99

IR (KBr): ν=3490, 3394, 3172, 2950, 2873, 1378, 1286, 1182, 1122, 1093cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.10-1.19 (1H, m), 1.37 (1H, dt-like,J=3.5, 13 Hz), 1.45-1.64 (6H, m), 1.73 (1H, d-like, J=13 Hz), 1.82 (1H,dd-like, J=2.0, 13 Hz), 4.63-4.72 (1H, m), 5.30 (1H, s, OH), 7.01 (1H,d, J=8.2 Hz, OH) ppm

¹³C-NMR (150 MHz in DMSO-d6): δ=21.74, 21.89, 26.45, 29.85 (d, J=5.8Hz), 31.69 (d, J=2.9 Hz), 67.0-68.2 (m), 74.16 (t, J=24 Hz), 121.93 (dd,J=251, 264 Hz), 125.67 (q, J=285 Hz) ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−127.87(1F, dd, J=17, 258 Hz), −123.52 (1F, dq, J=17, 255 Hz), −73.52 (3F, dt,J=17, 7 Hz) ppm

<5-2> Synthesis of1-(2-hydroxy-1,1,3,3,3-pentafluoropropyl)-1-cyclohexyl methacrylate

Reaction was performed as in <1-3> of Example 1 aside from using 10 g ofthe diol compound obtained in <5-1> instead of the diol compoundobtained in <1-2>. A crude product was obtained. In this example, thestirring time at room temperature was 120 hours, and the crude productwas a 5:95 mixture of the target compound and the regioisomer. By silicagel chromatography, the crude product was separated into 550 mg (yield4%) of the target compound (fluorinated ester compound) and 8.0 g (yield63%) of the regioisomer.

1-(2-hydroxy-1,1,3,3,3-pentafluoropropyl)-1-cyclohexyl methacrylate(target compound)

colorless viscous liquid

GC-MS (EI): (m/z)⁺=41, 69, 87, 131, 210

¹H-NMR (600 MHz in DMSO-d6): δ=1.32-1.43 (2H; m), 1.45-1.71 (6H, m),1.93 (3H, s), 2.54-2.65 (2H, m), 4.66 (1H, dq, J=29, 8 Hz), 5.73 (1H, t,J=1.5 Hz), 6.10 (1H, q, J=1, 1.7 Hz), 7.32 (1H, d, J=8 Hz, OH) ppm

¹³C-NMR (150 MHz in DMSO-d6): δ=19.63, 22.33, 22.68, 25.66, 29.57,30.36, 68.40-69.40 (m), 85.68 (t, J=25 Hz), 120.44 (dd, J=254, 263 Hz),125.24 (q, J=285 Hz), 127.45, 138.04, 166.26 ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic-acid standard): δ=−122.40(1F, ddq-like, J=264, 22, 9 Hz), −115.72 (1F, dq-like, J=264, 17 Hz),−73.57 (3F, dt-like, J=17, 9 Hz) ppm

3-(1-hydroxycyclohexyl)-1,1,1,3,3-pentafluoro-2-propyl methacrylate(regioisomer)

colorless viscous liquid

GC-MS (EI): (m/z)⁺=41, 69, 81, 99, 316 (M⁺)

IR (NaCl): ν=3531, 2940, 2865, 1745, 1637, 1454, 1382, 1336, 1280, 1189,1139, 1052 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.08-1.17 (1H, m), 1.35-1.41 (2H, m),1.41-1.64 (6H, m), 1.73-1.78 (1H, m), 1.97 (3H, dd, J=1.0, 1.4 Hz), 5.63(1H, s), 5.97 (1H, quint-like, J=1.4 Hz), 6.05-6.12 (1H, m), 6.23 (1H,t-like, J=1.0 Hz) ppm

¹³C-NMR (150 MHz in DMSO-d6): δ=19.10, 21.55, 21.67, 26.14, 29.83 (d,J=4.3 Hz), 30.68, 65.9-67.0 (m), 74.07 (t, J=24 Hz), 121.04 (dd, J=251,265 Hz), 123.77 (q, J=283 Hz), 130.90, 135.32, 165.35 ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−123.86(1F, dd-like, J=13, 264 Hz), −121.25 (1F, dq-like, J=264, 17 Hz), −72.11(3F, dt-like, J=17, 6.5 Hz) ppm

Example 6 Synthesis of1-(2-hydroxy-1,1,3,3,3-pentafluoropropyl)-1-cyclohexyl methacrylate(exemplary use of protective group)

<6-1> Synthesis of1-(1,1,3,3,3-pentafluoro-2-trimethyl-silyloxypropyl)-1-cyclohexylmethacrylate

With stirring at 5° C. under nitrogen atmosphere, 1.03 ml ofchlorotrimethylsilane was added dropwise to a mixture of 2.0 g of thediol compound obtained in <5-1> of Example 5, 20 ml of triethylamine, 20ml of methylene chloride and 5 ml of tetrahydrofuran. The mixture waswarmed to room temperature before it was stirred for one hour.Thereafter, 650 μl of methacryloyl chloride was added to the reactionmixture, which was heated at 70° C. and stirred for 30 hours. Aftercooling, the reaction mixture was mixed with 80 ml of water andextracted with methylene chloride. Through conventional work-upprocedure including washing, drying and concentration, a crude productwas obtained. It was used in the subsequent step without purification.

1-(1,1,3,3,3-pentafluoro-2-trimethylsilyloxypropyl)-1-cyclohexylmethacrylate

GC-MS (EI): (m/z)⁺=41, 69, 87, 131, 193, 213, 282, 388 (M⁺)

<6-2> Synthesis of1-(2-hydroxy-1,1,3,3,3-pentafluoropropyl)-1-cyclohexyl methacrylate

A tetrahydrofuran solution of 1.0M tetra-n-butylammonium fluoride, 10ml, was added to a solution of the crude product of <6-1> in 6 ml oftetrahydrofuran, followed by stirring at room temperature for 18 hours.The reaction mixture was mixed with 80 ml of 15% hydrochloric acid andextracted with ethyl acetate. Through conventional work-up procedureincluding washing, drying and concentration, a crude product wasobtained.

The crude product was a 85:15 mixture of the target compound and itsregioisomer. By silica gel chromatography, the crude product wasseparated into 1.7 g (yield 67%) of the target compound (fluorinatedester compound) and 0.2 g (yield 8%) of the regioisomer. Theirspectroscopic properties were identical with those of Example 5.

Example 7 Synthesis of 3-hydroxy-2,2,4,4,4-pentafluoro-1-phenylbutylmethacrylate

<7-1> Synthesis of 3-oxo-2,2,4,4,4-pentafluoro-1-phenyl-1-butanolequivalent

Reaction was performed as in <1-1> of Example 1 aside from using 30 g ofbenzaldehyde instead of the 2-adamantanone in <1-1>. A crude product wasobtained. Recrystallization from n-hexane gave 62.3 g (yield 79%) of ahydrate which was an equivalent of the target ketoalcohol compound.

3,3-dihydroxy-2,2,4,4,4-pentafluoro-1-phenyl-1-butanol

colorless solid

IR (KBr): ν=3532, 1492, 1456, 1288, 1251, 1207, 1164, 1099, 1074, 1066cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=5.26 (d, J=22 Hz), 6.98 (1H, br. d, J=3Hz, OH), 7.33-7.45 (6H, m), 8.18 (1H, d, J=2 Hz) ppm

¹⁹F-NMR (283 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−128.95(1F, ddq, J=260, 22, 10 Hz), −177.03 (1F, ddq, J=260, 10, 3 Hz), −80.31(3F, t, J=10 Hz) ppm

<7-2> Synthesis of 3-hydroxy-2,2,4,4,4-pentafluoro-1-phenyl-1-butanol

Reaction was performed as in <5-1> of Example 5 aside from using 30 g ofthe hydrate of ketoalcohol compound equivalent obtained in <7-1> insteadof the hydrate of ketoalcohol compound equivalent obtained in <2-1>.There was obtained a crude product, which was distilled in vacuo,collecting 25 g (yield 89%) of the target diol compound.

3-hydroxy-2,2,4,4,4-pentafluoro-1-phenyl-1-butanol (43:57 diastereomermixture)

pale yellow viscous liquid

boiling point: 115° C./53 Pa

IR (NaCl): ν=3372, 2940, 1456, 1373, 1276, 1224, 1174, 1137, 1112, 1060,1031 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=4.22-4.32 (0.43H, m), 4.69 (0.57H, dq,J=30, 7 Hz), 4.99 (0.43H, dt, J=5, 13 Hz), 5.04 (0.57H, dd, J=4, 24 Hz),6.43 (0.43H, d, J=5 Hz, OH), 6.49 (0.57H, d, J=4 Hz, OH), 7.30-7.56 (6H,m) ppm

¹³C-NMR (150 MHz in DMSO-d6): δ=67.5-68.5 (m, major), 68.6-69.3 (m,minor), 71.35 (dd, J=20, 32 Hz, major), 72.94 (t, J=25 Hz, minor),120.92 (dd, J=251, 256 Hz, minor), 121.48 (t, J=254 Hz, major), 125.12(q, J=285 Hz, minor), 125.66 (q, J=283 Hz, major), 129.31 (major+minor),129.46 (major), 129.50 (minor), 129.70 (minor), 129.80 (major), 138.48(major), 138.86 (minor) ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−126.51(0.57F, dhex-like, J=258, 14 Hz), −122.72 (0.43F, dhex-like, J=256, 9Hz), −122.64 (0.57F, dhex-like, J=256, 9 Hz), −122.02 (0.43F, dhex-like,J=256, 11 Hz), −73.70 (0.43×3F, dt-like, J=7, 15 Hz), −73.28 (0.57×3F,dt-like, J=7, 15 Hz) ppm

<7-3> Synthesis of 3-hydroxy-2,2,4,4,4-pentafluoro-1-phenylbutylmethacrylate

Reaction was performed as in <1-3> of Example 1 aside from using 11.1 gof the diol compound obtained in <7-2> instead of the diol compoundobtained in <1-2>. A crude product was obtained. The reaction wasmonitored by gas chromatography, finding a higher proportion of aregioisomer at the initial (target compound:regioisomer=23:77immediately after dropwise addition), subsequent gradual isomerizationinto the target compound, and substantial conversion to the targetcompound after 24 hours. The crude product was purified by silica gelchromatography, to give 7.5 g (yield 53%) of the target fluorinatedester compound.

3-hydroxy-2,2,4,4,4-pentafluoro-1-phenylbutyl methacrylate (40:60diastereomer mixture)

pale yellow viscous liquid

IR (NaCl): ν=3434, 2985, 1731, 1378, 1280, 1151 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.96 (0.4×3H, s), 1.98 (0.6×3H, s),4.23-4.33 (0.4H, m), 4.62-4.73 (0.6H, m), 5.85-5.88 (0.4H+0.6H, m), 6.12(0.6H, d, J=3 Hz, OH), 6.15 (0.4H, d, J=3 Hz, OH), 6.25 (0.4H, t, J=1.0Hz), 6.26-6.32 (0.4H+0.6×2H, m), 7.20-7.78 (0.4×5H+0.6×5H, m) ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−122.50(0.4F, ddq-like, J=260, 26, 10 Hz), −121.60 (0.6F, dhex-like, J=262, 10Hz), −120.20 (0.6F, dhex-like, J=262, 10 Hz), −118.65 (0.4F,dquint-like, J=26, 10 Hz), −73.82 (0.4F, q-like, J=10 Hz), −73.56 (0.6F,quint-like, J=7 Hz) ppm

Example 8 Synthesis of1-(1,1,3,3,3-pentafluoro-2-trimethylsilyloxy-propyl)-1-cyclohexylacrylate

Reaction was performed as in <6-1> of Example 6 aside from usingacryloyl chloride instead of the methacryloyl chloride in <6-1>. From2.0 g of the diol compound obtained in <5-1>, 1.5 g (yield 50%) of thetarget fluorinated ester compound having a hydroxyl group protected wasobtained.

1-(1,1,3,3,3-pentafluoro-2-trimethylsilyloxypropyl)-1-cyclohexylacrylate

GC-MS (EI): (m/z)⁺=55, 77, 131, 153, 193, 213, 267, 359

Example 9 Synthesis of1-(2-hydroxy-1,1,3,3,3-pentafluoropropyl)-1-cyclohexyl acrylate

Reaction was performed as in <6-2> of Example 6 except that thefluorinated ester compound having a protected hydroxyl group obtained inExample 8 was used instead of the crude product obtained in <6-1>,obtaining the target fluorinated ester compound.

1-(2-hydroxy-1,1,3,3,3-pentafluoropropyl)-1-cyclohexyl acrylate

GC-MS (EI): (m/z)⁺=55, 73, 131, 153, 192, 210

GC-MS (CI, isobutane): (m/z)⁺=73, 173, 193, 211, 265, 303 [(M+H)⁺]

Example 10 Synthesis of1-(2-hydroxy-2-methyl-1,1,3,3,3-pentafluoro-propyl)-1-cyclohexylα-trifluoromethylacrylate

The target compound was obtained as in <1-3> of Example 1 using the diolcompound obtained in <2-2> instead of the diol compound obtained in<1-2> and α-trifluoromethylacryloyl chloride instead of methacryloylchloride.

1-(2-hydroxy-2-methyl-1,1,3,3,3-pentafluoropropyl)-1-cyclohexylα-trifluoromethylacrylate

GC-MS (EI): (m/z)⁺=81, 123, 131, 221, 364 [(M−HF)⁺]

GC-MS (CI, isobutane): (m/z)⁺=141, 207, 225, 245, 385 [(M+H)⁺]

Example 11 Synthesis of 1-ethyl-3-hydroxy-2,2,4,4,4-pentafluorobutylmethacrylate

<11-1> Synthesis of 2-oxo-1,1,1,3,3-pentafluoro-4-hexanol equivalent

Synthesis was performed as in <1-1> of Example 1 aside from usingpropionaldehyde instead of the 2-adamantanone in <1-1>. A crude productwas obtained in solid form. The crude product washed with hexane anddried in vacuo, to give a hydrate which was an equivalent of the targetketoalcohol compound, that is, 1,1,1,3,3-pentafluoro-2,2,4-hexanetriolin colorless solid form (yield 65%). The physical properties of thiscompound were identical with the data reported by Nakai et al., OrganicSyntheses, Vol. 76, pp. 151 (1998).

<11-2> Synthesis of 1,1,1,3,3-pentafluoro-2,4-hexanediol

A mixture of 100 g of the triol compound obtained in <11-1>, 400 g oftetrahydrofuran and 200 g of water was stirred at 5° C., to which amixture of 17 g of sodium borohydride and 200 g of water was addeddropwise over one hour. The reaction mixture was slowly warmed up toroom temperature and then stirred for 16 hours. The reaction wasquenched by adding 100 g of 20% hydrochloric acid. Through conventionalwork-up procedure including washing, drying and concentration, a crudeproduct was obtained. Vacuum distillation gave 86 g (yield 93%) of1,1,1,3,3-pentafluoro-2,4-hexanediol.

1,1,1,3,3-pentafluoro-2,4-hexanediol (mixture of two diastereomers)

boiling point: 82° C./600 Pa

colorless solid at room temperature

IR (KBr): ν=3403 (br.), 2985, 2954, 2890, 1465, 1446, 1382, 1371, 1280,1232, 1176, 1153, 1110, 1058, 1024, 989, 848, 840, 829, 690, 680 cm⁻¹

¹H-NMR of major diastereomer (600 MHz in DMSO-d6): δ=0.93 (3H, t, J=7.6Hz), 1.42 (1H, m), 1.60 (1H, m), 3.72 (1H, m), 4.50 (1H, m), 5.57 (1H,d, J=6.5 Hz), 7.13 (1H, d, J=7.9 Hz) ppm

<11-3> Synthesis of 1-ethyl-3-hydroxy-2,2,4,4,4-pentafluorobutylmethacrylate

Synthesis was performed as in <1-3> of Example 1 aside from using thediol compound obtained in <11-2> instead of the diol compound obtainedin <1-2>. The resulting crude product was purified by silica gel columnchromatography, to give the target fluorinated ester compound (yield85%).

1-ethyl-3-hydroxy-2,2,4,4,4-pentafluorobutyl methacrylate (Mixture ofTwo Diastereomers)

colorless liquid

GC-MS (EI): (m/z)⁺=41, 69, 87, 170, 276 (M⁺)

GC-MS (CI, methane)=(m/z)⁺=87, 115, 171, 237, 257, 277 [(M+H)⁺]

Example 12 Synthesis of1-cyclohexyl-3-hydroxy-2,2,4,4,4-pentafluorobutyl methacrylate

<12-1> Synthesis of 1-cyclohexyl-2-oxo-2,2,4,4,4-pentafluoro-1-butanolequivalent

Synthesis was performed as in <1-1> of Example 1 aside from usingcyclohexanecarbaldehyde instead of the 2-adamantanone in <1-1>. Therewas obtained a hydrate which was an equivalent of the target ketoalcoholcompound (yield 72%).

1-cyclohexyl-2,2,4,4,4-pentafluorobutane-1,3,3-triol

colorless solid

IR (KBr): ν=3558, 3334 (br.), 3093, 2942, 2859, 1454, 1373, 1303, 1216,1207, 1164, 1116, 1099, 1074, 1068, 1043, 993, 887, 871, 796, 734 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.02-1.32 (5H, m), 1.53 (1H, m), 1.58(1H, m), 1.69 (2H, m), 1.77 (2H, m), 3.88 (1H, m), 5.83 (1H, d, J=6.5Hz), 7.50 (1H, s), 7.90 (1H, d, J=1.0 Hz) ppm

<12-2> Synthesis of 1-cyclohexyl-2,2,4,4,4-pentafluorobutane-1,3-diol

Synthesis was performed as in <11-2> of Example 11 aside from using thetriol compound obtained in <12-1> instead of the triol compound obtainedin <11-1>. The target diol compound was obtained in a quantitativeyield.

1-cyclohexyl-2,2,4,4,4-pentafluorobutane-1,3-diol (mixture of twodiastereomers)

colorless solid

IR (KBr): ν=3394 (br.), 3257 (br.), 2931, 2859, 1456, 1417, 1378, 1359,1268, 1224, 1193, 1184, 1151, 1118, 1091, 1056, 1025, 998, 948, 881,869, 831, 705, 682 cm⁻¹

¹H-NMR of major diastereomer (600 MHz in DMSO-d6): δ=1.00-1.30 (5H, m),1.55-1.80 (6H, m), 3.54 (1H, ddt, J=6.9, 2.4, 9.7 Hz), 4.49 (1H, m),5.48 (1H, d, J=6.9 Hz), 7.14 (1H, d, J=7.9 Hz) ppm

<12-3> Synthesis of 1-cyclohexyl-3-hydroxy-2,2,4,4,4-pentafluorobutylmethacrylate

Synthesis was performed as in <1-3> of Example 1 aside from using thediol compound obtained in <12-2> instead of the diol compound obtainedin <1-2>. The resulting crude product was purified by silica gel columnchromatography, to give the target fluorinated ester compound (yield75%).

1-cyclohexyl-3-hydroxy-2,2,4,4,4-pentafluorobutyl methacrylate (mixtureof two diastereomers)

colorless liquid

IR (NaCl): ν=3446 (br.), 2933, 2858, 1710, 1637, 1454, 1380, 1351, 1278,1226, 1170, 1112, 1027, 950, 827, 686 cm⁻¹

¹H-NMR of major diastereomer (600 MHz in DMSO-d6): δ=0.95-1.30 (5H, m),1.58 (2H, m), 1.67 (2H, m), 1.79 (1H, m), 1.90-2.00 (4H, m), 4.70 (1H,m), 5.27 (1H, ddd, J=19.9, 8.3, 2.8 Hz), 5.77 (1H, m), 6.11 (1H, m),7.55 (1H, d, J=7.6 Hz) ppm

¹³C-NMR (150 MHz in DMSO-d6): δ=17.84, 17.93, 25.30, 25.45, 25.55,25.67, 25.91, 25.93, 27.10, 30.14, 36.49, 36.51, 36.63, 67.23 (m), 67.89(m), 72.58 (dd, J=32, 22 Hz), 73.57 (t, J=21 Hz), 119.84 (t, J=255 Hz),120.38 (t, J=254 Hz), 123.53 (q, J=284 Hz), 123.70 (q, J=284 Hz),126.81, 135.18, 135.21, 165.10, 165.59 ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−120.97(0.35F, dm, J=262 Hz), -117.97 (0.35F, dm, J=262 Hz), −117.35 (0.65F,dm, J=259 Hz), −115.28 (0.65F, dm, J=259 Hz), −73.70 (1.95F, m), 73.54(1.05F, m) ppm

Example 13 Synthesis of1-(2-adamantyl)-3-hydroxy-2,2,4,4,4-pentafluorobutyl methacrylate

<13-1> Synthesis of1-(2-adamantyl)-3-oxo-2,2,4,4,4-pentafluoro-1-butanol equivalent

Synthesis was performed as in <1-1> of Example 1 aside from using2-adamantanecarbaldehyde instead of the 2-adamantanone in <1-1>. Therewas obtained an equivalent of the target ketoalcohol compound in hydrateform (yield 73%).

1-(2-adamantyl)-2,2,4,4,4-pentafluorobutane-1,3,3-triol

colorless solid

IR (KBr): ν=3563, 3450 (br.), 3384 (br.), 2917, 2854, 1456, 1380, 1276,1230, 1213, 1199, 1182, 1139, 1091, 1054, 1035, 997, 973, 937, 908, 877,829, 709 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.50-1.58 (2H, m), 1.70-1.77 (4H, m),1.77-1.94 (6H, m), 2.02 (1H, m), 2.06-2.12 (2H, m), 4.43 (1H, m), 6.53(1H, br. d, J=5.5 Hz), 7.43 (1H, br. s), 8.04 (1H, br. s) ppm

<13-2> Synthesis of 1-(2-adamantyl)-2,2,4,4,4-pentafluorobutane-1,3-diol

Synthesis was performed as in <11-2> of Example 11 aside from using thetriol compound obtained in <13-1> instead of the triol compound obtainedin <11-1>. The target diol compound was obtained in a quantitativeyield.

1-(2-adamantyl)-2,2,4,4,4-pentafluorobutane-1,3-diol (mixture of twodiastereomers)

colorless solid

IR (KBr): ν=3426 (br.), 3249 (br.), 2908, 2850, 1456, 1378, 1274, 1230,1203, 1174, 1141, 1120, 1106, 1091, 1074, 1056, 1041, 1034, 1002, 885,844, 819 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.45-1.50 (2H, m), 1.60-1.90 (10H, m),1.90-2.05 (2H, m), 2.07 (1H, m), 3.94 (0.74H, m), 4.08 (0.26H, dt,J=24.1, 9.1 Hz), 4.50-4.60 (1H, m), 5.49 (0.26H, br. d, J=8.6 Hz), 5.72(0.74H, d, J=7.2 Hz), 7.07 (0.74H, d, J=7.6 Hz), 7.19 (0.26H, br. d,J=7.2 Hz) ppm

<13-3> Synthesis of 1-(2-adamantyl)-3-hydroxy-2,2,4,4,4-pentafluorobutylmethacrylate

Synthesis was performed as in <1-3> of Example 1 aside from using thediol compound obtained in <13-2> instead of the diol compound obtainedin <1-2>. The resulting crude product was purified by silica gel columnchromatography, to give the target fluorinated ester compound (yield81%).

1-(2-adamantyl)-3-hydroxy-2,2,4,4,4-pentafluorobutyl methacrylate(mixture of two diastereomers)

colorless liquid

IR (NaCl): ν=3446 (br.), 2912, 2856, 1710, 1637, 1456, 1380, 1342, 1276,1218, 1168, 1116, 1025, 946, 819, 811 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.46 (1H, m), 1.59 (1H, m), 1.68-1.89(10H, m), 1.90 (3H, m), 2.07 (1H, m), 2.22 (0.24H, br. d, J=10.3 Hz),2.33 (0.76H, br. d, 10.0 Hz), 4.28 (0.24H, m), 4.51 (0.76H, m),5.60-5.70 (1H, m), 5.73 (0.24H, br. s), 5.76 (0.76H, br. s), 6.09(0.24H, br. s), 6.11 (0.76H, br. s), 7.28 (0.24H, d, J=7.9 Hz), 7.38(0.76H, d, J=7.9 Hz) ppm

¹³C-NMR (150 MHz in DMSO-d6): δ=17.59, 17.72, 26.56, 26.66, 26.91,27.47, 27.61, 28.27 (d-like, J=5 Hz), 28.47 (d-like, J=4 Hz), 31.24,31.34, 31.45, 31.49, 37.08, 37.09, 37.77, 37.89, 38.03, 38.07, 89.08,39.22, 42.97 (d-like, J=2 Hz), 42.57 (d-like, J=3 Hz), 67.10 (ddq, J=22,30, 30 Hz), 67.72 (m), 69.68 (dd, J=32, 26 Hz), 71.43 (dd, J=27, 24 Hz),119.46 (dd, J=258, 251 Hz), 120.73 (t, J=255 Hz), 123.32 (q, J=285 Hz),123.51 (q, J=285 Hz), 126.50, 126.75, 134.89, 135.07, 164.68, 169.97 ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard):

δ=−119.08 (0.24F, dm, J=264 Hz), −118.98 (0.76F, dm, J=265 Hz), −118.42(0.24F, dm, J=264 Hz), −112.92 (0.76F, dm, J=265 Hz), −73.5-73.4 (3F, m)ppm

Example 14 Synthesis of1-(1-adamantyl)-3-hydroxy-2,2,4,4,4-pentafluorobutyl methacrylate

<14-1> Synthesis of1-(1-adamantyl)-3-oxo-2,2,4,4,4-pentafluoro-1-butanol equivalent

Synthesis was performed as in <1-1> of Example 1 aside from using1-adamantanecarbaldehyde instead of the 2-adamantanone in <1-1>. Therewas obtained an equivalent of the target ketoalcohol compound in hydrateform (yield 83%).

1-(1-adamantyl)-2,2,4,4,4-pentafluorobutane-1,3,3-triol

colorless solid

IR (KBr): ν=3411 (br.), 3243 (br.), 2908, 2850, 1454, 1344, 1290, 1267,1211, 1193, 1149, 1110, 1093, 1072, 1039, 867 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.60 (3H, dm, J=11.3 Hz), 1.65 (3H, dm,J=11.3 Hz), 1.68 (3H, dm, J=14.1 Hz), 1.69 (3H, dm, J=14.1 Hz), 1.98(3H, m), 3.71 (1H, br. d, J=27 Hz), 6.38 (1H, br.), 7.33 (1H, br.), 8.00(1H, br.) ppm

<14-2> Synthesis of 1-(1-adamantyl)-2,2,4,4,4-pentafluorobutane-1,3-diol

Synthesis was performed as in <11-2> of Example 11 aside from using thetriol compound obtained in <14-1> instead of the triol compound obtainedin <11-1>. The target diol compound was obtained (yield 99%).

1-(1-adamantyl)-2,2,4,4,4-pentafluorobutane-1,3-diol (mixture of twodiastereomers)

colorless solid

IR (KBr): ν=3482 (br.), 3376 (br.), 2906, 2850, 1450, 1407, 1361, 1265,1203, 1187, 1160, 1147, 1137, 1103, 1087, 1054, 1045, 1024, 987, 971,877, 833, 819, 761 cm⁻¹

¹H-NMR of major diastereomer (600 MHz in DMSO-d6): δ=1.61 (3H, dm,J=11.7 Hz), 1.64 (3H, dm, J=11.7 Hz), 1.67 (3H, dm, J=12.7 Hz), 1.72(3H, dm, J=12.7 Hz), 1.92 (3H, m), 3.23 (1H, dm, J=24.4 Hz), 4.53 (1H,m), 5.58 (1H, br. d, J=6.2 Hz), 7.01(1H, m) ppm

<14-3> Synthesis of 1-(1-adamantyl)-3-hydroxy-2,2,4,4,4-pentafluorobutylmethacrylate

Synthesis was performed as in <1-3> of Example 1 aside from using thediol compound obtained in <14-2> instead of the diol compound obtainedin <1-2>. The resulting crude product was purified by silica gel columnchromatography, to give the target fluorinated ester compound (yield85%).

1-(1-adamantyl)-3-hydroxy-2,2,4,4,4-pentafluorobutyl methacrylate(mixture of two diastereomers)

colorless solid

IR (KBr): ν=3386 (br.), 2915, 2854, 1718, 1639, 1452, 1407, 1384, 1365,1351, 1344, 1315, 1299, 1274, 1218, 1164, 1114, 1025, 1016, 941, 854,827, 813, 759, 682 cm⁻¹

¹H-NMR of major diastereomer (600 MHz in DMSO-d6): δ=1.58-1.75 (12H, m),1.90-1.95 (6H, m), 4.14 (1H, m), 5.38 (1H, dd, J=25.7, 3.1 Hz), 5.78(1H, m), 6.13 (1H, m), 7.34 (1H, m) ppm

¹³C-NMR of major diastereomer (150 MHz in DMSO-d6): δ=19.51, 29.00,37.68, 38.69, 39.53, 69.03 (ddq, J=22, 30, 30 Hz), 75.73 (dd, J=32, 22Hz), 123.42 (t, J=257 Hz), 125.17 (q, J=285 Hz), 128.34, 136.74, 166.32ppm

¹⁹F-NMR of major diastereomer (565 MHz in DMSO-d6, trifluoroacetic acidstandard): δ=−117.77 (1F, ddq, J=262, 22, 10 Hz), −116.04 (1F, ddq,J=262, 27, 14 Hz), −73.22 (3F, ddd, J=14, 10, 8 Hz) ppm

Example 15 Synthesis of 3-hydroxy-2,2,4,4,4-pentafluorobutylmethacrylate

<15-1> Synthesis of 2,2,4,4,4-pentafluoro-1,3-butanediol

With stirring in a nitrogen atmosphere, a mixture of 109 g of1,1,1,3,3,3-hexafluoro-2-propanol and 500 g of tetrahydrofuran wascooled to 5° C. To the mixture, 500 ml of 2.71M n-butyllithium inn-hexane was added dropwise. The mixture was stirred at 5° C. for 2hours, after which 19.5 g of formaldehyde was added. The mixture wasstirred at 5° C. for one hour and then at room temperature for 18 hours.To the reaction mixture, 500 g of water and a mixture of 37.0 g ofsodium borohydride and 300 g of water were sequentially added dropwise.The mixture was stirred at room temperature for 10 hours. The reactionwas quenched by adding 330 g of 20% hydrochloric acid. Throughconventional work-up procedure including washing, drying andconcentration, there was obtained a crude product. It was distilled invacuo for purification, to give 58.3 g of the target compound,2,2,4,4,4-pentafluoro-1,3-butanediol (boiling point 90-100° C./1660 Pa,yield 50%).

GC-MS (EI): (m/z)⁺=30, 51, 63, 80, 113, 132

GC-MS (CI, methane): (m/z)⁺=141, 161, 181 [(M+H)⁺]

<15-2> Synthesis of 3-hydroxy-2,2,4,4,4-pentafluorobutyl methacrylate

A mixture of 10 g of the 2,2,4,4,4-pentafluoro-1,3-butanediol obtainedin <15-1>, 9.6 g of methacrylic acid, 1.1 g of p-toluenesulfonic acid,and 30 g of toluene was heated under reflux for 3 hours while the waterformed by reaction was being distilled off. The reaction mixture wascooled to room temperature and then subjected to conventional work-upprocedure including washing, drying and concentration. The resultingcrude product was purified by silica gel column chromatography, to give9.9 g (yield 72%) of the target fluorinated ester compound.

3-hydroxy-2,2,4,4,4-pentafluorobutyl methacrylate

colorless liquid

GC-MS (EI): (m/z)⁺=41, 69, 86, 99, 248 (M⁺)

GC-MS (CI, methane): (m/z)⁺=69, 181, 209, 229, 249 [(M+H)⁺]

Example 16 Synthesis of2,2-dimethyl-3-hydroxy-2,2,4,4,4-pentafluoro-butyl methacrylate

<16-1> Synthesis of 4-methyl-1,1,1,3,3-pentafluoropentane-2,4-diol

The target diol compound was obtained (yield 71%) as in <15-1> ofExample 15 aside from using acetone instead of the formaldehyde.

4-methyl-1,1,1,3,3-pentafluoropentane-2,4-diol

boiling point: 105° C./1730 Pa

colorless solid at room temperature

IR (KBr): ν=3432 (br.), 3257 (br.), 3020, 3006, 2960, 2917, 2763, 1475,1461, 1394, 1376, 1359, 1282, 1259, 1224, 1191, 1174, 1155, 1112, 1095,1041, 970, 877, 835, 808, 694 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.22 (3H, s), 1.24 (3H, s), 4.62 (1H, m),5.46 (1H, br.), 7.05 (1H, m) ppm

<16-2> Synthesis of 2,2-dimethyl-3-hydroxy-2,2,4,4,4-pentafluorobutylmethacrylate

With stirring at 0° C., 24 g of chlorotrimethylsilane was added dropwiseto a mixture of 43 g of the4-methyl-1,1,1,3,3-pentafluoropentane-2,4-diol obtained in <16-1>, 52 gof triethylamine and 250 g of acetonitrile. The mixture was stirred forone hour, after which 26 g of methacryloyl chloride was added dropwise.The mixture was stirred at 0° C. for 1 hour and then at room temperaturefor 16 hours. Then 50 g of 20% hydrochloric acid was added, followed bystirring at room temperature for 24 hours. Through conventional work-upprocedure including washing, drying and concentration, there wasobtained a crude product. It was distilled in vacuo, to give 36 g (yield63%) of the target fluorinated ester compound.

2,2-dimethyl-3-hydroxy-2,2,4,4,4-pentafluorobutyl methacrylate

boiling point: 56° C./40 Pa

colorless liquid

IR (NaCl): ν=3451 (br.), 3002, 2960, 2935, 1710, 1637, 1463, 1394, 1376,1336, 1309, 1286, 1263, 1193, 1157, 1105, 1049, 1010, 946, 848, 825,700, 661 cm⁻¹

¹H-NMR (600 MHz in DMSO-d6): δ=1.61 (3H, s), 1.66 (3H, s), 1.85 (3H, m),4.71 (1H, m), 5.69 (1H, m), 5.99 (1H, m), 7.32 (1H, br. d, J=7.6 Hz) ppm

¹³C-NMR (150 MHz in CDCl₃): δ=19.29, 20.70 (dd, J=6, 4 Hz), 21.67 (m),68.56 (ddq, J=22, 30, 30 Hz), 83.62 (dd, J=30, 24 Hz), 120.09 (dd,J=259, 255 Hz), 125.28 (q, J=285 Hz), 127.78, 137.88, 166.14 ppm

¹⁹F-NMR (565 MHz in DMSO-d6, trifluoroacetic acid standard): δ=−127.78(1F, ddq, J=261, 21, 8 Hz), −119.57 (1F, dq, J=261, 17), −73.70 (3F, dt,J=17, 8 Hz) ppm

Example 17 Synthesis of1,3-di(trifluoromethyl)-3-hydroxy-2,2,4,4,4-pentafluorobutylmethacrylate

<17-1> Synthesis of2-trifluoromethyl-1,1,1,3,3,5,5,5-octafluoropentane-2,4-diol

The target diol compound was obtained (yield 67%) as in <15-1> ofExample 15 aside from using hexafluoroacetone instead of theformaldehyde.

<17-2> Synthesis of1,3-di(trifluoromethyl)-3-hydroxy-2,2,4,4,4-pentafluorobutylmethacrylate

Reaction was performed as in <1-3> of Example 1 aside from using thediol compound obtained in <17-1> instead of the diol compound obtainedin <1-2>. The resulting crude product was purified by silica gel columnchromatography, to give the target fluorinated ester compound (yield77%).

Example 18 Synthesis of3-difluoromethyl-3-hydroxy-2,2,4,4,4-pentafluoro-1-trifluoromethylbutylmethacrylate

<18-1> Synthesis of2-difluoromethyl-1,1,1,3,3,5,5,5-octafluoropentane-2,4-diol

In a nitrogen atmosphere, a mixture of 109 g of1,1,1,3,3,3-hexafluoro-2-propanol and 500 g of tetrahydrofuran wascooled at 5° C. while stirring. To the mixture, 500 ml of 2.71Mn-butyllithium in n-hexane was added dropwise, followed by stirring at5° C. for 2 hours. To the reaction mixture, a mixture of 6.0 g of waterand 50 g of tetrahydrofuran was added dropwise over 2 hours. The mixturewas stirred at 5° C. for 1 hour and then at room temperature for 16hours. To the reaction mixture, 500 g of water and a mixture of 25 g ofsodium borohydride and 300 g of water were sequentially added dropwise.The mixture was stirred at room temperature for 24 hours. The reactionwas quenched by adding 260 g of 20% hydrochloric acid. Throughconventional work-up procedure including washing, drying andconcentration, there was obtained a crude product. It was distilled invacuo for purification, to give 53 g (yield 55%) of the target diolcompound in colorless liquid form.

2-difluoromethyl-1,1,1,3,3,5,5,5-octafluoropentane-2,4-diol (mixture oftwo diastereomers)

boiling point: 115° C./13300 Pa

colorless liquid

¹H-NMR (600 MHz in DMSO-d6): δ=4.69 (0.7H, dm, J=14.0, HO—CH), 4.78(0.3H, dm, J=20.6 Hz, HO—CH), 6.53 (0.7H, t, J=51.7 Hz, —CF₂ H), 6.61(0.3H, t, J=50.8 Hz, —CF₂ H), 7.64 (0.7H, br., CH—OH), 7.95 (0.3H, br.,CH—OH), 8.65 (0.7H, br. ≡C—OH), 8.88 (0.3H, br. ≡C—OH) ppm

<18-2> Synthesis of3-difluoromethyl-3-hydroxy-2,2,4,4,4-pentafluoro-1-trifluoromethylbutylmethacrylate

Reaction was performed as in <1-3> of Example 1 aside from using thediol compound obtained in <18-1> instead of the diol compound obtainedin <1-2>. The resulting crude product was purified by silica gel columnchromatography, to give the target fluorinated ester compound (yield78%).

3-difluoromethyl-3-hydroxy-2,2,4,4,4-pentafluoro-1-trifluoromethylbutylmethacrylate (mixture of two diastereomers)

colorless liquid

GC-MS (EI): (m/z)⁺=41, 69, 86, 113, 197, 347, 366 (M⁺)

GC-MS (CI, methane): (m/z)⁺=69, 243, 259, 299, 347, 367 [(M+H)⁺]

Japanese Patent Application No. 2003-348104 is incorporated herein byreference.

Although some preferred embodiments have been described, manymodifications and variations may be made thereto in light of the aboveteachings. It is therefore to be understood that the invention may bepracticed otherwise than as specifically described without departingfrom the scope of the appended claims.

1. A polymerizable fluorinated ester compound having the general formula(1) or (2):

wherein R¹ is hydrogen, methyl or trifluoromethyl, R² and R³ are eachindependently hydrogen or a monovalent hydrocarbon group of 1 to 15carbon atoms which may contain at least one hetero atom, a pair of R²and R³ may bond together to form a ring with the carbon atom to whichthey are bonded, and each of R² and R³ is a divalent hydrocarbon groupof 1 to 15 carbon atoms which may contain at least one hetero atom whenthey form a ring, R⁴ is hydrogen, hydroxyl, or a monovalent hydrocarbongroup of 1 to 15 carbon atoms which may contain at least one heteroatom, and R⁵ is an acid labile group.
 2. A process for preparing apolymerizable fluorinated ester compound having the general formula (1),comprising the steps of reacting a ketoalcohol compound having thegeneral formula (3) with a compound of the general formula: R⁴—Z to forma diol compound having the general formula (4), and acylating the diolcompound to form a polymerizable fluorinated ester compound having thegeneral formula (1):

wherein R¹ is hydrogen, methyl or trifluoromethyl, R² and R³ are eachindependently hydrogen or a monovalent hydrocarbon group of 1 to 15carbon atoms which may contain at least one hetero atom, a pair of R²and R³ may bond together to form a ring with the carbon atom to whichthey are bonded, and each of R² and R³ is a divalent hydrocarbon groupof 1 to 15 carbon atoms which may contain at least one hetero atom whenthey form a ring, R⁴ is hydrogen, hydroxyl, or a monovalent hydrocarbongroup of 1 to 15 carbon atoms which may contain at least one heteroatom, and Z is such a monovalent group that R⁴—Z provides a R⁴ anionequivalent.
 3. A process for preparing a polymerizable fluorinated estercompound having the general formula (1), comprising the steps ofreacting a ketoalcohol compound having the general formula (3) with acompound of the general formula: R⁴—Z to form a diol compound having thegeneral formula (4), protecting the diol compound to form an alcoholcompound having the general formula (5), acylating the alcohol compoundto form a protected polymerizable fluorinated ester compound having thegeneral formula (6), and deprotecting the compound of formula (6) into apolymerizable fluorinated ester compound having the general formula (1):

wherein R¹ is hydrogen, methyl or trifluoromethyl, R² and R³ are eachindependently hydrogen or a monovalent hydrocarbon group of 1 to 15carbon atoms which may contain at least one hetero atom, a pair of R²and R³ may bond together to form a ring with the carbon atom to whichthey are bonded, and each of R² and R³ is a divalent hydrocarbon groupof 1 to 15 carbon atoms which may contain at least one hetero atom whenthey form a ring, R⁴ is hydrogen, hydroxyl, or a monovalent hydrocarbongroup of 1 to 15 carbon atoms which may contain at least one heteroatom, R⁶ is a protective group, and Z is such a monovalent group thatR⁴—Z provides a R⁴ anion equivalent.
 4. A process for preparing apolymerizable fluorinated ester compound having the general formula (2),comprising the steps of reacting a ketoalcohol compound having thegeneral formula (3) with a compound of the general formula: R⁴—Z to forma diol compound having the general formula (4), protecting the diolcompound with an acid labile group to form an alcohol compound havingthe general formula (7), and acylating the alcohol compound to form apolymerizable fluorinated ester compound having the general formula (2):

wherein R¹ is hydrogen, methyl or trifluoromethyl, R² and R³ are eachindependently hydrogen or a monovalent hydrocarbon group of 1 to 15carbon atoms which may contain at least one hetero atom, a pair of R²and R³ may bond together to form a ring with the carbon atom to whichthey are bonded, and each of R² and R³ is a divalent hydrocarbon groupof 1 to 15 carbon atoms which may contain at least one hetero atom whenthey form a ring, R⁴ is hydrogen, hydroxyl, or a monovalent hydrocarbongroup of 1 to 15 carbon atoms which may contain at least one heteroatom, R⁵ is an acid labile group, and Z is such a monovalent group thatR⁴—Z provides a R⁴ anion equivalent.
 5. A process for preparing apolymerizable fluorinated ester compound having the general formula (2),comprising the step of protecting a polymerizable fluorinated estercompound having the general formula (1) with an acid labile group toform a polymerizable fluorinated ester compound having the generalformula (2):

wherein R¹ is hydrogen, methyl or trifluoromethyl, R² and R³ are eachindependently hydrogen or a monovalent hydrocarbon group of 1 to 15carbon atoms which may contain at least one hetero atom, a pair of R²and R³ may bond together to form a ring with the carbon atom to whichthey are bonded, and each of R² and R³ is a divalent hydrocarbon groupof 1 to 15 carbon atoms which may contain at least one hetero atom whenthey form a ring, R⁴ is hydrogen, hydroxyl, or a monovalent hydrocarbongroup of 1 to 15 carbon atoms which may contain at least one heteroatom, and R⁵ is an acid labile group.